Polycrystalline diamond cutter with integral polycrystalline diamond lined passage

ABSTRACT

Provided are polycrystalline diamond cutters including a substrate, a diamond body, and a passage extending through the cutter along an axis from an opening in a lower side of the substrate to an opening in a first side of a diamond body. The diamond body may have a planar oriented portion and a projecting portion. The planar oriented portion of the diamond body may be attached to the upper side of the substrate and the projecting portion of the diamond body may form at least a portion of an inner wall surface of the first passage.

CROSS-REFERENCE TO RELATED APPLICATIONS

None

TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY

The present disclosure relates generally to polycrystalline diamond cutters. Specifically, the present disclosure relates to polycrystalline diamond cutters incorporating an axially oriented passage through the cutter that is lined with polycrystalline diamond and methods to manufacture such polycrystalline diamond cutters.

BACKGROUND

In the discussion that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art against the present invention.

Tools used in the drilling industry, such as drag bits 10 (see FIG. 1), often incorporate multiple polycrystalline diamond cutters 20 arranged along a periphery region of a fin or blade 30 of the drag bit 10.

FIG. 2A shows a schematic perspective view of a conventional cylindrical shaped polycrystalline diamond cutter 20. The cutter 20 has a substrate 40, which is made of hard metal, alloy, or composite, and most typically of cemented carbide or cobalt sintered tungsten carbide (WC—Co), and a polycrystalline diamond composite volume 50 (also called a diamond table) attached or joined coherently to the substrate along the interface 60. Often, the catalyst, such as cobalt metal or its alloys, is present as a diamond bond-forming aid in high pressure and high temperature (HPHT) manufacturing of the polycrystalline diamond cutter 20.

Diamond tables and polycrystalline diamond cutters can be formed by sintering diamond particles under high pressure and high temperature conditions in the presence of a metal catalyst, such as cobalt (Co). The metal catalyst can originate from an independent source, such as a metal catalyst powder blended into the diamond particles or metal catalyst powder or foil adjacent the diamond particles or from a substrate material as described below. Conventional HPHT conditions include pressures at or above about 4-5 GPa and temperatures at or above about 1200° C. Typically, under the HPHT processing conditions, binder material present in an independent source or in a substrate (typically a cemented carbide substrate) positioned adjacent to diamond powders melts and sweeps into the mass of diamond. When a substrate is present, the binder material of the substrate can act as a metal catalyst in the diamond powders. In the presence of the metal catalyst, diamond crystals are bonded to each other in diamond-to-diamond bonds by a dissolution-precipitation process to form a sintered compact in which polycrystalline diamond mass, i.e., a diamond table, is formed which is attached to the substrate (if present). The presence of the metal catalyst facilitates formation of diamond-to-diamond bonds and, where applicable, the attachment of the diamond table to the substrate. However, the metal catalyst remains in the diamond table after the HPHT sintering process, and the presence of the metal catalyst is detrimental to polycrystalline diamond performance when used in cutting and machining applications. In particular, the presence of the metal catalyst in the sintered polycrystalline diamond compact may have detrimental effects on the mechanical properties of the polycrystalline diamond cutter when used in intended applications, such as drilling geologic formations.

The polycrystalline diamond cutter 20 may be later machined to a desired shape, including machining to specified outer diameter, height and the addition of any chamfers or beveled surfaces. Examples of chamfers or beveled surfaces 70 can be seen in side view in FIG. 2B, along with other surfaces of the polycrystalline diamond cutter 20, such as the top surface 80, and side surface 90. All or portions of the top surface, bevel surface and side surface can be the working surface of the polycrystalline diamond cutter 20, i.e. a surface of the polycrystalline diamond cutter 20 that contacts the geological formation being drilled.

Commonly, a polycrystalline diamond cutter is made using a high pressure and high temperature (HPHT) sweep-through process. In the sweep-through process, a mass of diamond crystals is placed into a refractory metal container. The diamond mass may contain some binder material or additives blended in to promote sintering. A cemented carbide substrate is placed in the container such that a surface of the substrate touches the mass of diamond crystals. The assembly is then subjected to HPHT conditions. Typically the binder material present in the substrate melts and sweeps into the mass of diamond crystals. In the presence of the liquefied binder material, diamond crystals bond to each other by a dissolution-precipitation process to form a polycrystalline diamond mass attached to the cemented carbide substrate.

The cemented carbide substrate usually includes small amounts of a binder material, such as cobalt, nickel, iron or their alloys, to improve integrity and strength. The binder material is generally selected to function as a catalyst for melting and sintering the diamond crystals. That is, in existing processes for forming a polycrystalline diamond cutter, the cobalt or other binder material from the substrate will melt under HPHT conditions from the carbide substrate and “sweep” across the diamond powder to create the polycrystalline diamond cutter. The sweep occurs as a front that moves from an interface between the substrate and the diamond crystals toward a distal surface of the diamond. If the interface between the substrate and the diamond is planar, the sweep may be uniform.

Polycrystalline diamond demonstrates wear and thermal properties that are advantageous in drilling operations. However, the presence in polycrystalline diamond compacts of catalyst promotes degradation of the cutting edge of the cutter during the cutting process, especially if the edge temperature reaches a high enough critical value. Probably, this catalyst driven degradation is caused by the graphitization of diamond. Such graphitization is known to occur at temperatures of about 700° C. and above and can cause ruptures to occur in the diamond-to-diamond bonding, and eventually result in the formation of cracks and chips in the polycrystalline diamond structure, rendering the polycrystalline diamond cutter unsuited for further use.

SUMMARY

For polycrystalline diamond cutters, it would be beneficial to mitigate thermally induced degradation. Thus, there is a need for structures and techniques that provide thermal management of the polycrystalline diamond cutter to improve the wear and thermal performance.

In one embodiment, a polycrystalline diamond cutter, comprises a substrate including an upper side, a lower side opposite the upper side, and at least one edge side connecting the upper side to the lower side, a diamond body including a planar oriented portion and a projecting portion, and a first passage extending through the cutter along an axis from a first opening in the lower side of the substrate to a second opening in a first side of the diamond body, wherein the planar oriented portion of the diamond body is attached to the upper side of the substrate, and wherein the projecting portion of the diamond body forms at least a portion of an inner wall surface of the first passage.

In another embodiment, a method of making a polycrystalline diamond cutter comprises forming an assembly, wherein the assembly comprises a substrate having a channel extending through a body of the substrate from a first opening in a lower side to a second opening in an upper side, a layer of diamond feed in contact with surfaces of the channel and with one of the lower side and upper side, and a refractory container including a tube portion inserted into the channel, adding poisoned diamond feed into an interior volume of the tube portion to form a poisoned assembly, and processing the poisoned assembly at elevated temperature and elevated pressure sufficient to sinter the diamond feed into a diamond body, wherein the diamond body includes a planar oriented portion attached to one of the lower side and upper side of the substrate, and wherein the diamond body includes a projecting portion attached to surfaces of the channel and forming at least a portion of an inner wall surface of a passage extending through the cutter on an axis.

In a further embodiment, a method of making a polycrystalline diamond cutter comprises forming an assembly, wherein the assembly comprises a substrate having a channel extending through a body of the substrate from a first opening in a lower side to a second opening in an upper side, a layer of diamond feed in contact with surfaces of the channel and with one of the lower side and upper side, and a refractory container, processing the assembly at elevated temperature and elevated pressure sufficient to sinter the diamond feed into a diamond body, wherein the diamond body includes a planar oriented portion attached to one of the lower side and upper side of the substrate, and wherein the diamond body includes a projecting portion filling the channel, and making a passage extending through the polycrystalline diamond cutter along an axis from a first opening in the lower side of the substrate to a second opening in a first side of the diamond body.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown.

FIG. 1 shows an example of a tool used in the drilling industry, in this case a conventional drag bit.

FIG. 2A shows a schematic perspective view of a conventional cylindrical shaped polycrystalline diamond cutter and FIG. 2B shows a conventional cylindrical shaped polycrystalline diamond cutter in cross-sectional view and with chamfers or beveled surfaces at an edge of the diamond table.

FIGS. 3A and 3B show exemplary embodiments of a cylindrical shaped polycrystalline diamond cutter with a passage extending through the cutter on an axis in assembled perspective view (FIG. 3A) and exploded cross-sectional view (FIG. 3B).

FIG. 4 is a graphical schematic of exemplary methods to manufacture a polycrystalline diamond cutter with a passage extending through the cutter on an axis.

FIG. 5 is a graphical schematic of additional exemplary methods to manufacture a polycrystalline diamond cutter with a passage extending through the cutter on an axis.

FIGS. 6A and 6B are each a schematic, cross-sectional perspective view of an exemplary embodiment of refractory container that is shaped with a tube portion.

FIGS. 7A to 7D schematically illustrate the preparation of an embodiment of an assembly and an embodiment of a poisoned assembly.

FIG. 8 is a schematic, cross-sectional view of another exemplary embodiment of a poisoned assembly showing the contents and arrangements of features.

FIGS. 9A and 9B are schematic, cross-sectional views of another exemplary embodiment of an assembly (FIG. 9A) and another exemplary embodiment of a poisoned assembly (FIG. 9B) showing the contents and arrangements of features.

FIG. 9C is a schematic, cross-sectional view of another exemplary embodiment of a poisoned assembly showing the contents and arrangements of features.

FIG. 9D is a schematic, cross-sectional view of a formed polycrystalline diamond cutter that can be produced using the assembly in FIG. 9A and the poisoned assembly in FIG. 9B or FIG. 9C.

FIGS. 10A to 10C are schematic, cross-sectional views of exemplary embodiment of assemblies that are prepared using a refractory container without a tube portion and showing three variations of structures that can be used to seal the assembly.

FIG. 10D is a schematic, cross-sectional view of another exemplary embodiment of an assembly that is prepared using a refractory container without a tube portion in which the substrate is loaded in the refractory container before the diamond feed is added and in which a sealing structure as in FIG. 1C is utilized.

FIGS. 11A and 11B are schematic, cross-sectional views of exemplary embodiment of assemblies illustrating examples of different configurations for the channel in the substrate and the arrangement of diamond feed in the channels.

FIGS. 12A to 12D illustrate, in schematic, cross-sectional view, alternative embodiments of formed polycrystalline diamond cutters.

FIG. 13 is a schematic cross-section of a substrate with a passage extending through the cutter on an axis before incorporating the substrate into an assembly.

FIGS. 14 to 19 show exemplary polycrystalline diamond cutters in cross-sectional view and with various geometries of a passage extending through the cutter on an axis; the protruding portion of the diamond body is shown variously as extending along the complete length of the passage or along less than the complete length of the passage.

FIG. 20 illustrates an example of an assembly that includes a metal catalyst solid in the form of a metal disc positioned at the bottom of the substrate on an axially opposite side of the substrate from the diamond-substrate interface whereby, during processing, infiltration of catalyst metal from two sources can contribute to attachment of the diamond table to the substrate.

FIG. 21 is a schematic, cut-away, partial view of an exemplary drilling tool with internal branching passages for cooling media and incorporating polycrystalline diamond cutters with a passage extending through the cutter on an axis.

DETAILED DESCRIPTION

FIGS. 3A and 3B show exemplary embodiments of a cylindrical shaped polycrystalline diamond cutter with a passage extending through the cutter on an axis. In the exemplary embodiment, the polycrystalline diamond cutter 100 comprises a substrate 110, a diamond body 120 and a passage 130 that extends through the cutter 100 on an axis 140. FIG. 3A shows these features in an assembled perspective view. FIG. 3B shows these features in an exploded, cross-sectional view.

The substrate 110 has body 150 with an upper side 160, a lower side 170 opposite the upper side 160, and at least one edge side 180 connecting the upper side 160 and the lower side 170, e.g., at a corner 190. For example, when the cutter 100 is in the shape of a cylinder, the outer cylindrical surface is the at least one edge side. In addition, the substrate has a channel 200 that extends through the substrate body 150 from a first opening 210 in the lower side 170 to a second opening 220 in the upper side 160. Typically, the channel 200 is a bore having a cylindrical shape and is coaxially located with axis 140. However, the channel 200 can be other shapes or can be offset from axis 140 or angled with respect to axis 140 or one or more of these variations from that depicted in FIG. 3B. In the assembled form of the cutter 100, at least a portion of the surface 230 of the channel 200, alternatively all of the surface 230 of the channel 200 will be in contact with a portion of the diamond body 120.

The diamond body 120 includes a planar oriented portion 240 and a projecting portion 250 and is continuous from the radial outer edge side of the planar oriented portion 240 to an axially most distant end of the projecting portion 250. The planar oriented portion 240 lies in a plane substantially perpendicular to axis 140 and has an upper side 260 and a lower side 270 and a thickness L₁, in the axial direction, i.e., parallel to axis 140, of about 0.5 mm to 5.0 mm, alternatively about 2.0 mm. An edge side 280 connects the upper side 260 and the lower side 270, e.g., at a corner 290. The projecting portion 250 protrudes from the lower side 270 of the planar portion 250 a distance L₂ in a direction substantially parallel, alternatively coaxial with, axis 140 and terminates in a distal end 300. The projecting portion 250 has outer surface 310 and a passage 320 that extends from a first opening 330 in the upper side 260 of the planar oriented portion 240 to second opening 340 at the distal end 300 of the projecting portion 250 and has an inner surface 350. In exemplary embodiments, the passage 310 is coaxial with axis 140 and is also coaxial with channel 200 of the substrate 110. In the exemplary embodiment shown, the surface 360 of the distal end 300 is planar and is oriented in a plane perpendicular to the axis 140 and, when viewed along axis 140, forms an annulus.

In the assembled form of the cutter 100, the planar oriented portion 240 of the diamond body 120 is attached to the upper side 160 of the substrate 110. Additionally, in the assembled form of the cutter 100, the projecting portion 250 of the diamond body 120 is located within at least a portion of the channel 200 in the substrate 110 and is attached to at least a portion of the surface 230 of the channel 200 to form at least a portion of an inner wall surface; alternatively the projecting portion 250 is attached to and runs the length of the entire surface 230 of the channel 200.

The composition of the diamond body can be sintered diamond particle sizes between about 1 micron to about 50 microns and a catalyst metal phase between about 8 percent by weight (wt. %) to about 25 percent by weight (wt. %). The diamond body 120 is formed integrally to the substrate through a high pressure—high temperature sintering process as described herein during which metal catalyst diffuses into the diamond body and not only densifies the diamond body, but also serves to mechanically bond the diamond body to the substrate.

The substrate 110 can be any suitable substrate that can be processed in the high pressure—high temperature sintering environment used to consolidate and sinter the polycrystalline diamond particles into the diamond body and to bond the diamond body to the substrate. Further, the composition of the substrate typically includes a metal catalyst. In exemplary embodiments, the substrate is a hard metal alloy or composite, a cemented carbide, or cobalt sintered tungsten carbide (WC—Co). In preferred embodiments, the substrate is cobalt sintered tungsten carbide and has a composition of 8-15 wt. % cobalt and 85-92 wt. % tungsten carbide and, optionally, 0.3-2.5 wt. % chromium.

FIGS. 4 and 5 are graphical schematics of exemplary methods to manufacture a polycrystalline diamond cutter with a passage extending through the cutter on an axis. In general, methods of manufacture form an assembly for subsequent high pressure—high temperature processing during which polycrystalline diamond particles, with the aid of a metal catalyst, are consolidated and sintered into a diamond body that is bonded to the substrate. In some exemplary methods, i.e., FIG. 4, the assembly uses a refractory container that is shaped with a tube portion that imparts the feature of the passage in the polycrystalline diamond cutter during the high pressure—high temperature process. In other exemplary methods, i.e., FIG. 5, the assembly is formed and processed at high pressure—high temperature and then the feature of the passage in the polycrystalline diamond cutter is imparted through a separate manufacturing process applied to the diamond body. In both methods, however, the final form of the polycrystalline diamond cutter includes a passage extending through the cutter on an axis.

Before describing the methods in more detail, reference is made to FIGS. 6A and 6B, which are each a schematic, cross-sectional perspective view of an exemplary embodiment of refractory container that is shaped with a tube portion. The refractory containers 600,600′ are typically cylindrical in shape and include a bottom 610,610′ and side surfaces 620,620′. The refractory container containers 600,600′ are open at the top 630,630′ to allow for loading of contents during preparation of the assembly. A tube portion 640,640′ protrudes from the bottom 610,610′ into the interior volume of the refractory container 600,600′. The tube portion 640,640′ is joined to or integral to the material of the bottom 610,610′ and has an interior space 650,650′ that is separated from the interior volume of the refractory container 600,600′ by the tube portion 640,640′ itself, but the interior space 650,650′ is nevertheless accessible from the exterior of the refractory container 600,600′, i.e., through opening 660,660′. In the embodiment in FIG. 6A, the tube portion 640′ is of a constant diameter along its length and protrudes from the bottom 610 into the interior volume of the refractory container 600 a distance D, which is typically equal to the distance d of the side surfaces 620 from the bottom 610 to the top 630. In alternative embodiments, such as the embodiment in FIG. 6B, the distance D consists of a first port D1 can be less than the distance d; however, the distance D1 generally is at least as long as the distance of the passage to be formed in the polycrystalline diamond cutter. In other exemplary embodiments, such as the embodiment in FIG. 6B, the tube portion 640′ has a first tube portion 670 of a constant diameter along its length D1 and a second tube portion 680 having a shape to be imparted to the substrate formed in the assembly, such as the shape of a frustum of a cone or of a cylinder or of a one sheet hyperboloid. The second tube portion 680 is at the end of the tube portion 640′ that is toward the opening 660′ and has a length D2. The sum of the lengths D1 and D2 equals the distance d′ of the side surfaces 620′ from the bottom 610′ to the top 630′. Using an analogy, the refractory containers 600,600′, in several ways, resembles and functions like a Bundt pan in that it has a bottom, sides, an open top and a tube portion and in that the shape of the surfaces are transferred to the contents.

Although one embodiment of a refractory container includes a tube portion, such embodiments are preferably used when the tube portion imparts the feature of the passage or the feature of a shaped portion of the in the polycrystalline diamond cutter during the high pressure—high temperature process. Other embodiments of the refractory container without the tube portion feature can also be used, particularly where the feature of the passage in the polycrystalline diamond cutter is imparted through a separate manufacturing process applied to the diamond body.

The refractory container is typically made from a refractory alloy such as tantalum (Ta), niobium (Nb), molybdenum (Mo), and zirconium (Zr), with tantalum being the preferred material. The refractory container can be made by any suitable method. However, it is preferred that the refractory container is seamless and is formed by a sheet metal forming process that includes a drawing operation, preferably deep drawing. When a tube portion is present, it also can be formed by a sheet metal forming process that includes a drawing operation, preferably deep drawing.

Turning back to the methods and with reference to FIG. 4, a first exemplary method 400 comprises forming an assembly using a refractory container that is shaped with a tube portion, forming the assembly into a poisoned assembly, and high pressure—high temperature (HPHT) processing the poisoned assembly to form a polycrystalline diamond cutter with a passage extending through the cutter on an axis.

The assembly can be formed in one of several ways. In a first method, a layer of diamond feed is formed in the refractory container 410 a. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container that includes a tube portion. The diamond feed is distributed in a layer on the bottom of the refractory container and has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1 mm and 5 mm.

A substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 410 b. The substrate is positioned in the refractory container with the upper side of the substrate in contact with the layer of diamond feed. Additionally, the substrate is positioned such that the tube portion of the refractory container extends through the channel in the substrate.

Typically, the tube portion will extend through the channel and past the lower surface of the substrate. Also, there is typically a clearance space between the surfaces of the tube portion and the surfaces of the channel. Accordingly, diamond feed is added into this clearance space 410 c. The diamond feed added into the clearance space contacts the diamond feed already present in the layer of diamond feed formed previously (see 410 a) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the clearance space. The diamond feed in the clearance space can fill the entire clearance space consistent with the length of the channel, in which case the diamond body will be formed along the entire length of the channel. Alternatively, the diamond body can be formed along less than the entire length of the tube by using a substrate geometry which closes off the channel at the bottom, thereby preventing diamond from forming in the portion where the substrate is in direct contact with the tube wall. A geometric feature can be imparted to a portion of the diamond body, for example, the portion that corresponds to the distal portion of the projecting portion of the diamond body, by modifying the geometry of the substrate, such as with a chamfer, an angled surface, a concave surface, a convex surface, or a hyperbolic surface.

A cap is subsequently positioned over the opening of the refractory container to cover the contents of the refractory container and the capped refractory container is sealed to form an assembly 430. In one embodiment, the cap can have a shape similar to the container 600,600′ but without a tube portion and having a diameter of the opening that is sufficiently larger than the diameter of the container 600,600′ so that the cap can slide over at least a portion of the distance d of the outer peripheral surfaces of the container in a telescoping manner to form a container-over-container structure. This structure positions the bottom of the interior volume of the cap in contact with the opening 630,630′ in the container 600,600′. Once arranged into the structure, the container and the cap can be crimped or otherwise pressed together so as to seal the cap and the container to form an assembly. In another embodiment, the cap can be a disc or foil or similar planar structure that is placed in the opening 630,630′ of the container 600,600′ over the contents in the container 600,600′ and then the peripheral edge of the cap and the peripheral edge of the opening 630,630′ are crimped or otherwise pressed together or folded over so as to seal the cap and the container to form an assembly. Sealing can be by any suitable means that secures the cap to the refractory container and secures the contents of the assembly within the capped refractory container. The cap is typically of the same material as the refractory container, e.g., tantalum.

In a second method, a substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 420 a. The substrate is positioned in the refractory container with the lower side oriented toward the bottom of the refractory container and with the upper side oriented toward the open side of the refractory container. In addition, the substrate is positioned within the refractory container such that the tube portion of the refractory container extends through the channel in the substrate.

Typically, the tube portion will extend through the channel and past the upper surface of the substrate. Also, there is typically a clearance space between the surfaces of the tube portion and the surfaces of the channel. Accordingly, diamond feed is added into this clearance space 420 b. The diamond feed can be added by pouring or otherwise adding the diamond feed into the clearance space. The diamond feed in the clearance space can fill the entire clearance space consistent with the length of the channel, in which case the diamond body will be formed along the entire length of the channel. Alternatively, the diamond body can be formed along less than the entire length of the tube by using a substrate geometry which closes off the channel at the bottom, thereby preventing sintered diamond from forming in the portion where the substrate is in direct contact with the tube wall. A geometric feature can be imparted to a portion of the diamond body, for example, the portion that corresponds to the distal portion of the projecting portion of the diamond body, by modifying the geometry of the substrate, such as with a chamfer, an angled surface, a concave surface, a convex surface, or a hyperbolic surface.

After the axial length of the clearance space is filled, for example, when the diamond feed extends axially up to the level of the upper surface of the substrate, a layer of diamond feed is formed 420 c. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container that is above the upper surface of the substrate. The diamond feed added to form the layer contacts the diamond feed already present in the clearance space added previously (see 420 b) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the clearance space. Also, the diamond feed is distributed in a layer that is in contact with at least a portion of the upper surface, alternatively in contact with the entire upper surface. The layer has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1.0 mm and 4.0 mm.

A cap is subsequently positioned in the opening of the refractory container to cover the contents of the refractory container and the capped refractory container is sealed to form an assembly 430. In one embodiment, the cap can have a shape similar to the container 600/600′ but without a tube portion and having a diameter of the opening that is sufficiently larger than the diameter of the container 600,600′ so that the cap can slide over at least a portion of the distance d of the outer peripheral surfaces of the container in a telescoping manner to form a container-over-container structure. This structure positions the bottom of the interior volume of the cap in contact with the opening 630,630′ in the container 600,600′. Once arranged into the structure, the container and the cap can be crimped or otherwise pressed together so as to seal the cap and the container to form an assembly. In another embodiment, the cap can be a disc or foil or similar planar structure that is placed over the opening 630,630′ of the container 600,600′ over the contents in the container 600,600′ and then the peripheral edge of the cap and the peripheral edge of the opening 630,630′ are crimped or otherwise pressed together or folded over so as to seal the cap and the container to form an assembly. Sealing can be by any suitable means that secures the cap to the refractory container and secures the contents of the assembly within the capped refractory container. The cap is typically of the same material as the refractory container, e.g., tantalum.

Assemblies formed in the first method (410 a, 410 b, 410 c, 430) and formed in the second method (420 a, 420 b, 420 c, 430) can then be further prepared for processing under high pressure—high temperature (HPHT) processing. Further preparations include 440 placing a non-reactive material in the interior space 650,650′ of the tube portion 640,640′ of the refractory container, preferably to fill the interior space 650,650′. The non-reactive material should be capable of withstanding the high pressure—high temperature processing conditions without reacting with the contents of the assembly and while also transmitting the pressure applied to the assembly. The non-reactive material should also be capable of providing structural rigidity sufficient to approximately maintain the channel geometry at HPHT conditions. An example of a suitable non-reactive material is a diamond feed that has been poisoned to be non-reactive and non-sinterable. Such a poisoned diamond feed has a composition of between about 5 percent and 30 percent by weight talc powder, balance diamond powder. Another example of a suitable non-reactive material is salt. Assemblies to which a non-reactive material has been added are referred to herein as poisoned assemblies.

FIGS. 7A to 7D illustrate, in cut away view and in a step-wise fashion, the contents and arrangement of features during preparation of the assembly and poisoned assembly. In FIG. 7A, the diamond feed and substrate are shown loaded into a refractory container 705 that includes a tube portion 710. As seen in FIG. 7A, the diamond feed 715 is a bottom layer in the refractory container 705 and the substrate 720 is positioned inverted, e.g., top surface down, with the top surface in contact with the diamond layer 715. Also note that the clearance space 725 extends the entire axial length of the channel in the substrate 720 and is filled with additional diamond feed in continuous manner with the diamond feed 715 in the bottom layer.

FIG. 7B illustrates the refractory cup and contents of FIG. 7A with a cap 730 positioned over the outside of the refractory container 705 in telescoping fashion with the peripheral surfaces to form a container-over-container structure to form an assembly 700. When fully positioned over the refractory container 705, a portion 735 of the walls 740 of the cap 730 extends beyond the refractory container 705 and defines a volume 745 into which the non-reactive material 750 can be added (as seen in FIG. 7C). After adding the non-reactive material, a further cap 755 can be positioned over the outside of the first cap 730 in telescoping fashion with the peripheral surfaces of the first cap 730 forming a container-over-container structure, which can be sealed, for example by crimping the edges, to form a poisoned assembly 700′.

Although shown in step-wise fashion in FIGS. 7A to 7D, hereafter for other embodiments, the full step-wise views have not been shown, but rather only portions of the step wise views or only the final assembled structure has been shown. However, even when not shown directly the step-wise assembly can be readily inferred by analogy to the FIGS. 7A to 7D images. Also, although shown in a particular orientation, the refractory container, caps, assembly, intermediate structures, and poisoned assembly and can be orientated as necessary to facilitate the addition of components, such as the substrate, diamond feed, and non-reactive material, and the manipulation of the refractory container and cap(s).

FIG. 8 illustrates an exemplary embodiment of a poisoned assembly 800 in cut away view and showing the contents and arrangement of features. The completed poisoned assembly 800′ in FIG. 8 illustrates an embodiment where the substrate is placed first into the first refractory container and the diamond layer is then formed in the clearance space between the substrate and the tube portion and on top of the substrate. Over the course of subsequent steps, a first cap, poisoned diamond feed and a second cap are added. The schematic shown in FIG. 8 is analogous to the schematic shown in FIG. 7D, but the diamond layer is added on top of the substrate in the embodiment in FIG. 8 rather than the substrate being added on top of the diamond layer as in the embodiment in FIG. 7D. Also, no volume for additional non-reactive material is utilized in the embodiment of the poisoned assembly shown in FIG. 8.

In FIG. 8, the substrate 805 has been positioned in the refractory container 810 with a bottom surface of the substrate 805 in contact with the bottom of the refractory container 810. Subsequently, diamond feed 815 is added to the clearance space 820. The diamond feed 815 in the clearance space 820 extends the entire length of the tube portion 825. Once the clearance space 820 is filled, the diamond feed 815 then covers the top surface of the substrate 805 with a diamond layer 830. A first cap 835 is positioned over the refractory container 810 in telescoping fashion with the peripheral surfaces of the refractory container 810 and forms a container-over-container structure. Subsequently, non-reactive material 840 can be added to the interior space of the tube portion 825 through the opening in the refractory container 810. After adding the non-reactive material 840, a further cap 845 can be positioned over the outside of the first cap 835 in telescoping fashion with the peripheral surfaces of the first cap 835 to form a container-over-container structure, which can be sealed, for example by crimping the edges, to form a poisoned assembly 800.

In other embodiments discussed herein, the clearance space can extend only a portion of the entire axial length of the channel in the substrate. FIGS. 9A and 9B show a cut away view of an exemplary embodiment of an assembly 900′ and a poisoned assembly 900″ at two steps in the assembling process. In FIG. 9A, a substrate 905 is positioned in the refractory container 910 with a bottom surface of the substrate 905 in contact with the bottom of the refractory container 910. The substrate 905 has a channel extending through the substrate 905, but the surface of the channel is not arranged at a uniform distance from the centerline, i.e., the axis. Rather, the channel has a first portion 915 that is sized to conform with the size of the tube portion 920 of the refractory container 910 and a second portion 925 that is spaced from the tube portion 920 of the refractory container 910 to form the clearance space 930. After the substrate 905 is seated in the refractory container 910, diamond feed 935 is added to the clearance space 930 and extends the entire length of the second portion 925 of the tube portion 920. Once the clearance space 930 is filled, the diamond feed 935 then covers the top surface of the substrate 905 with a diamond layer 940.

As seen in FIG. 9A, a first cap 945 is then positioned over the refractory container 910 and forms a container-over-container structure. Subsequently and as seen in FIGS. 9B and 9C, non-reactive material 950 can be added to the interior space of the tube portion 920. The non-reactive material 950 can fill the interior space of the tube portion 920 and continue and form a layer 955 between the refractory container 910 and a second cap 960 (FIG. 9B) or the non-reactive material 950 can be limited to the interior space of the tube portion 920 (FIG. 9C). In both cases, after adding the non-reactive material 950, a further cap 960 can be positioned over the outside of the first cap 945 in telescoping fashion forming a container-over-container structure, which can be sealed, for example by crimping the edges, to form a poisoned assembly 900′.

One or more poisoned assemblies are loaded into a cell for high pressure—high temperature (HPHT) processing 450. Generally, the cell includes a pressure transmitting medium, a heater, the product assembly, and a thermal insulating material. An example of a suitable cell is disclosed in U.S. Pat. No. 4,807,402, the entire contents of which are incorporated herein by reference. The cell is then subjected to high pressure—high temperature (HPHT) processing conditions sufficient to consolidate and sinter the diamond feed into a diamond body that is bonded to the substrate. An example of suitable HPHT processing conditions includes temperatures in the range 1300° C. to 1700° C., pressures in the range 50 kbar to 80 kbar (5 GPa to 8 GPa), and sintering times between about 2 minutes to about 20 minutes. After removing the pressure and allowing the cell to cool, the cell and assembly can be opened and the polycrystalline diamond cutter recovered.

Using the embodiments shown in FIGS. 7A to 7D and FIG. 8, after further processing, a completed polycrystalline diamond cutter is formed in which the projecting portion of polycrystalline diamond extends the entire axial length of the channel. Using embodiments shown in FIGS. 9A to 9C, a completed polycrystalline diamond cutter 965 is formed with a diamond body 970 attached to a substrate 905. The projecting portion 975 of polycrystalline diamond body does not extend the entire axial length of the channel 980, but rather a portion of the axial length is occupied by a portion 985 of the substrate 910. Such a structure is shown in FIG. 9D.

Referring back to the methods and with reference to FIG. 5, further exemplary methods 500 comprise forming an assembly using a refractory container without a tube portion, high pressure—high temperature (HPHT) processing the assembly to form a polycrystalline diamond cutter, and making a passage extending through the cutter on an axis.

The assembly can be formed in one of several ways. In a third method, a layer of diamond feed is formed in the refractory container 510 a. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container. The diamond feed is distributed in a layer on the bottom of the refractory container and has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1 mm and 5 mm.

A substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 510 b. The substrate is positioned in the refractory container with the upper side of the substrate in contact with the layer of diamond feed. Diamond feed is then added into channel of the substrate 510 c. The diamond feed added into the channel contacts the diamond feed already present in the layer of diamond feed formed previously (see 510 a) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the channel. The diamond feed in the channel can fill the entire clearance space consistent with the length of the channel, in which case the diamond body will be formed along the entire length of the channel. A geometric feature can be imparted to a portion of the diamond body, for example by modifying the shape of channel, such as with a chamfer, an angled surface, a concave surface, a convex surface, or a hyperbolic surface.

To secure the contents of the assembly or poisoned assembly, a cap is placed over the opening of the refractory container or interior cap and sealed. In one embodiment, an example of which is shown in FIG. 10A, the assembly 1000 includes a layer 1005 of diamond feed in the bottom of the refractory container 1010 and a substrate 1015 placed in the refractory container 1010 with a top surface in contact with the layer 1005 of diamond feed. After filling the channel with further diamond feed 1020, a cap 1025 having a shape similar to the container 1010 but having a diameter of the opening that is sufficiently larger than the diameter of the container 1010 so that the cap 1025 can slide over at least a portion of the distance d of the outer peripheral surfaces of the container 1010 in a telescoping manner to form a container-over-container structure. This structure positions the bottom of the interior volume of the cap 1025 in contact with the opening in the container 1010. Once arranged into the structure, the container 1010 and the cap 1025 can be crimped or otherwise pressed together so as to seal the cap 1025 and the container 1010 to form the assembly 1000. Multiple telescoping caps can be used as necessary to accommodate the number and positioning of materials in the assembly and poisoned assembly (similar to the embodiments previously described in connection with a refractory container having a tube portion). In another embodiment, an example of which is shown in FIG. 10B, assembly 1000′ includes a cap 1030 in the form of a disc or foil or similar planar extending structure that is placed in the opening of the refractory container 1010 over the contents in the refractory container 1010 and then the peripheral edge of the cap 1030 and the peripheral edge of the opening of the refractory container 1010 are crimped or otherwise pressed together or folded over (see, for example, area 1035) so as to seal the cap 1030 and the container 1010 to form the assembly 1000′. In a further embodiment, an example of which is shown in FIG. 100, assembly 1000″ includes a cap 1040 in the form of a lid that is placed in the opening of the refractory container 1010 and has edges 1045 that extend beyond the edge of the opening and down a length of the outer periphery wall 1050 of the refractory container 1010 (or other structure that the lid is sealing). The cap 1040 extends over the contents in the refractory container 1010 and then the peripheral edge of the cap 1040 and the peripheral edge of the opening of the refractory container 1010 is crimped or otherwise pressed together or attached to the outer periphery wall 1050 of the refractory container 1010 (or other structure that the lid is sealing) (see, for example, area 1035) so as to seal the cap 1040 and the container 1010 to form the assembly 1000″. Sealing can be by any suitable means that secures the cap to the refractory container and secures the contents of the assembly within the capped refractory container. In whatever form, the cap is typically of the same material as the refractory container, e.g., tantalum.

In a fourth method, a substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 520 a. The substrate is positioned in the refractory container with the lower side oriented toward the bottom of the refractory container and with the upper side oriented toward the open side of the refractory container. Diamond feed is added into the channel of the substrate 520 b. The diamond feed can be added by pouring or otherwise adding the diamond feed into the channel. The diamond feed in the channel can fill the axial length of the channel, in which case the diamond body will be formed along the entire length of the channel.

After the axial length of the channel is filled, for example, the diamond feed extends axially up to the level of the upper surface of the substrate, a layer of diamond feed is formed 520 c. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container that is above the upper surface of the substrate. The diamond feed added to form the layer contacts the diamond feed already present in the channel added previously (see 520 b) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the channel. Also, the diamond feed is distributed in a layer that is in contact with at least a portion of the upper surface, alternatively in contact with the entire upper surface. The layer has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1.0 mm and 4.0 mm.

Similar to that described and show in connection with the embodiment in FIGS. 10A to 10C in which the substrate is placed into the refractory container in contact with an initial layer of diamond feed, a cap is subsequently positioned in the opening of the refractory container to cover the contents of the refractory container and the capped refractory container is sealed to form an assembly. The cap can be any suitable cap as disclosed here and sealing can be by any suitable means that secures the cap to the refractory container and secures the contents of the assembly within the capped refractory container.

FIG. 10D illustrates an exemplary embodiment of an assembly 1000″ associated with the fourth method in cut away view and showing the contents and arrangement of features. FIG. 10D also is related to and shares some features with the embodiments in FIGS. 10A to 100 and the assembly 1000′″ includes a refractory container 1010, a layer of diamond feed 1005, a substrate 1015, the diamond feed in the channel 1020 and a cap 1040. Note how, in the illustrated embodiment, the substrate 1015 is positioned in the refractory container 1010 first and with a bottom surface of the substrate 1015 in contact with the bottom of the refractory container. Then diamond feed is added first as diamond feed in the channel 1020 that extends the entire axial length of the channel and then as diamond feed forming the layer 1005. Once the diamond feed is added, the opening in the refractory container 1010 is covered by a cap structure (cap 1040 with edges 1045 that extend beyond the edge of the opening and down a length of the outer periphery wall 1050 of the refractory container 1010) similar to that shown and described in FIG. 100 and sealed to form an assembly 1000′″. However, any one of the cap structures disclosed herein can be used to form the assembly 1000′″.

FIGS. 11A and 11B are schematic, cross-sectional views of exemplary embodiment of assemblies illustrating examples of different configurations for the channel in the substrate and the arrangement of diamond feed in the channels. As way of non-limiting example, the assembly 1100 in FIG. 11A includes a channel 1105 comprising a series of connected linear surfaces 1110. The channel also includes a first region 1115 having a first width w and a second region 1120 having a second width W, where width W is larger than width w. A surface of the channel connects the first region 1115 to the second region 1120. In the illustrated embodiment, the surface of the first region 1115 is parallel to the surface of the second region 1120 and the connecting surface is at an angle to the surface of the first region 1115 and the surface of the second region 1120. Also as way of non-limiting example, the assembly 1100′ in FIG. 11B includes a channel 1125 comprising a series of connected surfaces 1130 and includes a first region 1135 having a first width w′ and a second region 1140 having a minimum width W, where width W is larger than width w′. A surface of the channel also connects the first region 1135 to the second region 1140. However in contrast to the embodiment in FIG. 11A, the surface of the second region 1140 illustrated in the embodiment in FIG. 11B has a curvature. Other variations and combinations of linear and curved surfaces can be used in other exemplary embodiments.

Returning to FIG. 5 and related disclosed methods, assemblies formed in the third method (510 a, 510 b, 510 c, 530) and assemblies formed in the fourth method (520 a, 520 b, 520 c, 530) can then be processed under high pressure—high temperature (HPHT) processing conditions 540. One or more assemblies are loaded into a cell for high pressure—high temperature (HPHT) processing. Generally, the cell includes a gasketing material which transmits pressure and retains the contents of the cell under pressure, a heating element, the assemblies, and insulating materials. An example of a suitable cell is disclosed in U.S. Pat. No. 4,807,402, the entire contents of which are incorporated herein by reference. The cell is then subjected to high pressure—high temperature (HPHT) processing conditions sufficient to consolidate and sinter the diamond feed into a diamond body that is bonded to the substrate. An example of suitable HPHT processing conditions includes pressures in the range of about 5 GPa to about 10 GPa and temperatures in the range of about 1100° C. to about 2000° C. for times up to 20-30 minutes. Conditions favorable for the present methods and structures fall within about 5 GPa to about 8 GPa and about 1300° C. to about 1700° C. for about 12-18 minutes. After recovery from the HPHT processed assemblies, a passage can be formed in the polycrystalline diamond cutter. For example, a passage can be made 550 that extends through the polycrystalline diamond cutter along an axis from a first opening in the lower side of the substrate to a second opening in a first side of the diamond body. The passage can be, but is not required to be, concentric to the axis of the protruding portion of the diamond body and concentric to the channel in the substrate. The passage can be made by any combination of suitable means, including by laser cutting or electrical discharge machining (EDM) or diamond wire shaping.

FIGS. 12A to 12D illustrate, in schematic, cross-sectional view, alternative embodiments of formed polycrystalline diamond cutters. The polycrystalline diamond cutters 1150 include the general features of a substrate 1155, a diamond body with a planar portion 1160 and a projecting portion 1165 and a passage 1170 extending through the cutter along an axis form a first opening in the lower side of the substrate to a second opening in a first side of the diamond body. The structure of the projecting portion 1165 and the passage 1170 varies between the embodiments. Some embodiments have a projecting portion 1165 that extends along the entire length of the passage 1170 (see, e.g., FIGS. 12A and 12C), while other embodiments have a projecting portion 1165 that extends only along a portion of the length of the passage 1170 (see, e.g., FIGS. 12B and 12D).

The alternative embodiments in FIGS. 12A to 12D can be produced using suitable means in which the passage can be formed in-situ or by post-sintering machining. For example, in-situ formation can use methods that form assemblies or poisoned assemblies using a refractory container that includes a tube portion. Such in-situ methods have been shown and described in connection with the first and second method and FIG. 4. In another example, post-sintering machining formation can use methods that form assemblies using a refractory container that does not include a tube portion. Such post-sintering machining methods have been shown and described in connection with the third and fourth method and FIG. 5. Also, it should be noted that polycrystalline diamond cutters formed in situ- can also be post-sintered machined to further process the passage to, for example, expand a diameter of the passage, shape the inner surfaces of the passage, thin, or remove the projecting portion of the diamond body from a portion of the length of the passage.

The various embodiments of the polycrystalline diamond cutter can be further processed to final form. Such processing can include finish wire shaping or grinding of the surfaces of the passage, lapping or grinding of the diamond body to planarize the top surface of the grinder, grinding to add a bevel or chamfer to the diamond body and/or substrate, rotational grinding to finish grind the cylindrical sides of the cutter, and leaching of the metal catalyst in one or more portions of the diamond body.

The features and geometry of the substrate and the diamond body that form the polycrystalline diamond cutter can vary.

For example, FIG. 13 is a schematic cross-section of a substrate with a channel extending through the cutter on an axis before incorporating the substrate into an assembly. As opposed to the straight, cylindrical channel shown, for example, in FIG. 3B, the channel 1210 in the substrate 1200 in FIG. 13 is in the shape of a one sheet hyperboloid concentric to axis 1220 that includes an inlet 1230 in a bottom surface 1240, a throat 1250 (indicated by dashed line, which is slightly tilted to indicate the throat is an opening) at the narrowest diameter (indicated by dashed line) and an outlet 1260 in a top surface 1270. Such a shape, as well as variations of the hyperboloid shape, can be sized to produce a venturi effect when media flows through the channel 1210. However, the channel need not follow venturi principles.

The diameter of the inlet 1230 and the outlet 1260 are both greater than the diameter of the throat 1250, but themselves can either be the same diameter or of different diameters to each other. The absolute and relative sizes of the inlet 1230, outlet 1260 and throat 1250 are such that a coolant liquid or suspension pass freely into the inlet, through the throat, and out from the outlet without blockage and in a manner that removes heat from the cutting edge of the diamond layer. In exemplary embodiments, the diameter of the inlet 1230 can be from about ½ to about ¼ the final diameter of the finished cutter, the diameter of the outlet 1260 can be from about ½ to about ¼ the final diameter of the finished cutter and the diameter of the throat 1250 can be from about ½ to about ¼ the final diameter of the finished cutter. A ratio of dimensions includes: (a) an outlet:inlet ratio between about 1.2-1.6 and (b) an outlet:throat ratio between about 2.0-2.7. Generally, proportions of the passage in the finished cutter, i.e., the channel finished with a portion of the diamond body, will preserve the general shape and parameters of the channel 1210 in the substrate 1200.

Other shapes and geometries of the channel can be used, including full or partial chamfers, angled surfaces, concave surfaces, convex surfaces, or hyperbolic surfaces.

FIGS. 14 to 19 show exemplary polycrystalline diamond cutters in cross-sectional view. In each of FIGS. 14-19, the polycrystalline diamond cutter 1300 comprises a substrate 1305, a diamond body 1310 and a passage 1315 that extends through the cutter 1300 on an axis 1320. However, in each of FIGS. 14-19, one or more of the substrate 1305 and the diamond body 1310 varies in one or more of its shape, geometry or position within the cutter 1300. For example, FIGS. 14-19 illustrate various geometries of a passage extending through the cutter on an axis as well as variations in the channel in the substrate and variations of the top surface of the substrate.

In the exemplary embodiment in FIG. 14, the substrate 1305 is substantially the same as that shown and described in connection with FIG. 13. In the illustrated cutter 1300, a diamond body 1310 has been formed on the top surface and in the entire axial length of the channel in the substrate 1305. For example, the manufacturing method outlined in connection with FIG. 4 can be used to form the diamond body 1310. In the exemplary embodiment in FIG. 14, diamond body 1310 has a planar oriented portion 1325 and a projecting portion 1330. A passage 1315 extends through the cutter 1300 along the axis 1320 from a first opening 1335 in the lower side 1340 of the 1305 to a second opening 1345 in the first side 1350 of the diamond body 1310. The surfaces of the passage 1315 conform to the shape of the channel in the substrate 1305 and, in this instance, have the geometric shape of a one sheet hyperboloid concentric to axis 1320. The diameter of the first opening 1335 is less than the diameter of the second opening 1345. The surfaces of the passage 1315 transition into the lower side 1340 of the substrate 1305 and the first side 1350 of the diamond body 1310 at respective openings 1335, 1345 and this transition can, as an example, be a curved surface as shown in FIG. 14. The thickness of the planar oriented portion 1325, i.e., the axial thickness, is typically between 1.5 mm and 4.0 mm; the thickness of the projecting portion 1330 through the passage 1315, i.e., the radial thickness, may vary with axial position or be uniform with axial position and is typically between 0.5 mm and 2.0 mm.

The first side 1350 of the diamond body 1310 has a bevel or chamfer surface 1355 at the corner where the first side 1350 connects to the side surface 1360 of the diamond body 1310. The bevel or chamfer surface 1355 may have a vertical height, i.e., length in the axial direction, of 0.5 mm and an angle of 45 degrees which may provide a particularly strong and fracture resistant tool component. The upper surface of the substrate 1305 also has a bevel or chamfer surface 1365 at the corner where the upper side of the substrate 1305 connects to the side surface 1370 of the substrate 1305 and the lower side of the diamond body 1310 has a surface conformally shaped to and in contact with this bevel or chamfer surface 1365. As seen in FIG. 14, the side surface 1360 of the diamond body 1310 is at the same radial distance from the axis 1320 as the side surface 1370 of the substrate 1305. Also, the projecting portion 1330 extends through the entire axial length of the channel in the substrate 1305 and the distal end of the projecting portion 1330 has a surface 1375 that is aligned with the lower side 1340 of the substrate 1305. FIG. 14 shows how the thickness of the planar oriented portion 1325 does not include any variation for the bevel or chamfer surface 1355, 1365 associated with the diamond body 1310 or substrate 1305.

In the exemplary embodiment in FIG. 15, the substrate 1305 is substantial the same as that shown and described in connection with FIGS. 13 and 14, except that potions of the surfaces of the channel of the substrate 1305, i.e., portions extending axially from the upper side of the substrate 1305 and a portion of the distance toward the lower side 1340 of the substrate 1305, are removed to a depth into the body of the substrate 1305 to form a cavity In the formed cutter 1300 in FIG. 15. This cavity is occupied by the projecting portion 1330 of the diamond body 1310. The diamond body 1310 has also been formed on the top surface of the substrate 1305 with a planar oriented portion 1325 in contact with the top surface and with beveled or chamfered surfaces as previously described.

In the embodiment illustrated in FIG. 15, the passage 1315 extends through the cutter 1300 along the axis 1320 from a first opening 1335 in the lower side 1340 of the substrate 1305 to a second opening 1345 in the first side 1350 of the diamond body 1310. However, one difference in the FIG. 15 embodiment compared to the FIG. 14 embodiment is that, in the FIG. 15 embodiment, the inner surface 1400 of the passage 1315 is a combination of surfaces of the diamond body 1310 and surfaces of the substrate 1305. For example, in a first region 1405, the inner surface 1400 of the passage 1315 is a surface of the protruding portion 1330 of the diamond body 1310; in a second region 1410, the inner surface 1400 of the passage 1315 is a surface of the substrate 1305. These two regions 1405, 1410 are joined at an interface 1415 but otherwise present a continuous surface across the interface 1415 that does not include a step feature.

The diamond body 1310 has a shoulder 1420 in the area of the second opening 1345. The shoulder 1420 has an increased radial thickness that provides more volume of diamond body 1310 and an increased wear life of the diamond body 1310 in the area of the shoulder 1420.

The cavity can be formed by machining of the substrate or can be formed in the substrate manufacturing process, for example, by pressing the geometry of the substrate (including the cavity) in a green body using powder metallurgical techniques. Using a suitably formed substrate, a manufacturing method outlined in connection with FIG. 4 can be used to form the diamond body 1310 illustrated in the cutter 1300 in FIG. 15, including the portion of the diamond body 1310 occupying the cavity.

In the embodiment illustrated in FIG. 16, the passage 1315 extends through the cutter 1300 along the axis 1320 from a first opening 1335 in the lower side 1340 of the substrate 1305 to a second opening 1345 in the first side 1350 of the diamond body 1310. However, one difference in the FIG. 16 embodiment compared to the FIG. 14 embodiment is that, in the FIG. 16 embodiment, the channel in the substrate 1305 and the passage 1315 in the cutter 1300 both have the shape of a cylinder, in this case a right cylinder, and not the shape of a one sheet hyperboloid. Another difference in the FIG. 16 embodiment compared to the FIG. 14 embodiment is that, in the FIG. 16 embodiment, the top surface of the substrate 1305 is a modulated surface 1500. By modulated surface, it is meant that the surface is not uniformly planar across its entire surface area, but rather a texture is formed by modulating the axial position of the surface as a function of radial position. The modulated surface 1500 can increase adherence of the diamond body 1310 to the substrate 1305.

The modulation can be periodic or aperiodic. The modulation can also provide a pattern in the top surface, for example the pattern as shown in U.S. Pat. No. 5,484,330, the entire disclosure of which is incorporated herein by reference. In the embodiment illustrated in FIG. 16, the modulated surface 1500 is an alternating series of ridges 1505 and grooves 1510 in the substrate 1305 arranged in concentric circles centered on the axis 1320 and the diamond body 1310 has been formed on the top surface of the substrate 1305 (including being formed on the modulated surface 1500) with the lower surface of the planar oriented portion 1325 including corresponding features to the modulated surface 1500, the corresponding features in contact with and conformal to the modulated surface 1500.

The cutter in FIG. 16 can be manufactured, for example, using the manufacturing methods outlined in connection with FIG. 4 or FIG. 5. Additionally, the modulated surface 1500 can be formed in situ to the process of forming of the substrate 1305, for example, by forming during pressing of a green body that is then consolidated into the substrate, i.e., in a sintering process, or can be machined into the top surface of the substrate 1305.

In the embodiment illustrated in FIG. 17, the passage 1315 extends through the cutter 1300 along the axis 1320 from a first opening 1335 in the lower side 1340 of the substrate 1305 to a second opening 1345 in the first side 1350 of the diamond body 1310. In this embodiment, the passage 1315 in the cutter 1300 has the shape of a cylinder. The channel in the substrate 1305 also has a corresponding shape of a cylinder. In the embodiment illustrated in FIG. 17, the second opening 1345 has a bevel or chamfer surface 1600 that connects the first side 1350 of the diamond body 1310 with the surfaces of the passage 1315. The bevel or chamfer surface 1600 may have a vertical height, i.e., length in the axial direction, of 0.5 mm to about 1 mm and an angle of 45 degrees which may provide a particularly strong and fracture resistant tool component.

The embodiment illustrated in FIG. 18 is a variation of the embodiment in FIG. 17, but with the passage 1315 located radially offset from the symmetric center of the cutter 1300. The channel in the substrate 1305 is similarly radially offset. The radial offset is represented by the distance R between the axis 1320 of the passage 1315 and the symmetry axis 1700 of the cutter 1300. In other respects, the features of the cutter 1300 in FIG. 18 are the same as those of the cutter 1300 in FIG. 17.

The cutters in FIGS. 17 and 18 can be manufactured using, for example, the manufacturing methods outlined in connection with FIG. 4 or FIG. 5. Additionally, the bevel or chamfer surface 1600 can be formed in situ to the process of forming of the diamond body 1310 or can be machined into the diamond body 1310 in a post-sintering process.

FIG. 19 is another exemplary embodiment of a polycrystalline diamond cutter 1300 that includes a passage 1315 that extends through the cutter 1300 along the axis 1320 from a first opening 1335 in the lower side 1340 of the substrate 1305 to a second opening 1345 in the first side 1350 of the diamond body 1310. In the embodiment illustrated in FIG. 19, the diamond body 1310 has a bevel or chamfer surface 1800 at the second opening 1345 where the first side 1350 of the diamond body 1310 transitions into the surfaces of the passage 1315. The bevel or chamfer surface 1800 can be any size. In the illustrated embodiment, the bevel or chamfer surface 1800 has a vertical height, i.e., length in the axial direction, which is the same as the thickness, i.e., axial thickness, of the planar oriented portion 1325. The bevel or chamfer surface 1800 incorporates an angle of 45 degrees which may provide a particularly strong and fracture resistant tool component. The top surface of the substrate 1305 also transitions into the surface of the channel in the substrate 1305 with a bevel or chamfer surface 1805.

In the embodiment illustrated in FIG. 19, the diamond body 1310 has a cylindrically shaped protruding portion 1330 that has a uniform thickness, i.e., radial thickness, for a majority of its axial length. At the distal end 1810 of the protruding portion 1330, the diamond body 1310 is tapered and the thickness, i.e., the radial thickness, varies linearly as a function of axial position. The tapering of the distal end 1810 can have the shape and features necessary to mate the cutter 1300 to a supply line of cooling media, i.e., gas or liquid, that will flow through the passage 1315 when in use. For example, the distal end 1810 can have an angled surface 1815. In addition, the combination of the bevel or chamfer surface 1800 at the outlet, the more narrow diameter of the passage in the majority of its axial length, and the tapering or bevel surface 1815 of the distal end 1810 can be sized to produce at least some venturi effect when media flows through the passage 1315. However, the passage need not follow venturi principles.

The cutter in FIG. 19 can be manufactured using, for example, the manufacturing methods outlined in connection with FIG. 4 or FIG. 5. Additionally, the bevel or chamfer surface 1800 and/or the angled surface 1815 can be formed in situ to the process of forming of the diamond body 1310 or can be machined into the diamond body 1310 in a post-sintering process. For example, if formed in situ, the tube portion of the refractory container can have the complementary shape to the bevel or chamfer surface 1800 and/or the angled surface 1815.

Although particular features discussed above were discussed in relation to particular cutters in FIGS. 14-19, it is contemplated that each of the particular features can be combined separately or collectively to form further variations of the cutters. For example, the passage surface with two regions in FIG. 15 can be combined with one or more of the offset passage axis of FIG. 18, the modulated surface of FIG. 17, the cylindrically shaped protruding portion of FIGS. 16-18 and the tapered distal end of FIG. 19. Other combinations amongst the features are also contemplated.

In general, the surfaces of the passage 1315 transition into the lower side 1340 of the substrate 1305 and into the first side 1350 of the diamond body 1310 at respective openings 1335, 1345. In exemplary embodiments, both transitions can be a curved surface as shown in FIG. 14. In other exemplary embodiments, one or more of the transitions can be a right angled surface as shown in FIG. 16. In still other exemplary embodiments, this transition can be in the form of a beveled or chamfered surface as shown in FIG. 19. Additionally, these various forms of transition surfaces can be intermixed and used in different combinations, such as one right angled surface and one beveled surface as shown in FIG. 17.

In general, the substrate can be manufactured to final shape or near final shape prior to use in the high pressure—high temperature manufacturing operation. For example, the substrate can be formed substantially in the shape of a solid body, such as any type of cylinder or any type of polyhedron, and a channel can be manufactured in the solid body by machining, such as by reaming or drilling. In the case of complex geometries for the substrate or for the channel in the substrate (for example, with the cavity as shown in FIG. 15, powder metallurgy techniques can be used to form a green body with near net shape geometry and then the substrate can be machined to final form before being processed in the high pressure—high temperature sintering environment used to consolidate and sinter the polycrystalline diamond particles into the diamond body and to bond the diamond body to the substrate.

The passage and the diamond body, particularly the protruding portion of the diamond body, can take any suitable geometry that allows for one or more of a cooling medium to be transported to the region of the diamond body through the passage, heat to be transported away from the diamond body through the diamond body itself and/or through contact with a medium in the passage, or combinations thereof. In exemplary embodiments, the passage is shaped to impart a venturi effect to the cooling medium. However, in other embodiments, the passage need not follow venturi principles.

Further, the size of the exit opening (i.e., the second opening when the passage is considered as supplying cooling media to the side of the cutter with the planar oriented portion) is between approximately 3 mm and 7 mm diameter, depending on the diameter of the cutter. Larger diameter cutters may use a larger exit hole opening. The size of the entrance hole (i.e., the first opening when the passage is considered as supplying cooling media to the side of the cutter with the planar oriented portion) lies within a similar range, but may be different from the size of the exit hole opening on a given cutter.

In alternative embodiments of the methods disclosed herein, assemblies and poisoned assemblies can employ metal catalyst solid, such as a foil or metal disc, placed at the bottom of the substrate opposite the diamond-substrate interface. A typical metal catalyst solid is a cobalt or cobalt alloy metal disc. The metal body is in direct contact with a portion of the diamond feed, particular a portion located in the channel and, during the HPHT processing, sweeps axially through the diamond feed in the channel. This typically occurs prior to the binder sweep from the substrate. The infiltration of catalyst metal from two sources—binder in the substrate and metal catalyst in foil or disc—contributes to attachment of the diamond table to the substrate. FIG. 20 illustrates an example of an assembly 1900 that includes a metal catalyst solid 1905 in the form of a metal disc positioned at the bottom of the substrate 1910 on an axially opposite side of the substrate from the diamond-substrate interface 1915. The metal catalyst solid 1905 is in contact with a portion of the diamond feed 1920 that is positioned in the channel of the substrate 1910. Although illustrated using an embodiment similar to FIG. 10D, the metal catalyst solid can be incorporated into any of the assemblies, poisoned assemblies and methods disclosed herein whether using a refractory container that is shaped with a tube portion or using a refractory container without a tube portion.

In a further variation, portions of the diamond body can be leached to remove metal catalyst material from interstitial regions. Removal of metal catalyst from the diamond body, particularly from portions of the diamond body that act as a working surface of the polycrystalline diamond cutter leaves interconnected network of pores and a residual metal catalyst (up to 10 vol. %) trapped inside the polycrystalline diamond body. The removal of metal catalyst, such as cobalt, from diamond bodies significantly improves abrasion resistance of the diamond body. Such leaching can occur in at least a portion of the diamond body and renders the diamond body in that portion substantially free of metal catalyst material. Leaching can occur, for example, by chemical etching in acids in which portions to be leached are exposed to an acid or a mixture of acids, such as aqua regia, for a period of time sufficient to dissolve the catalyst material to a depth from the surface of the diamond body. The time varies by strength of acid, temperature and pressure as well as the desired depth. Exemplary depths from which the catalyst material has been removed range from 50 microns to 800 microns, alternatively less than 300 microns or less than 200 microns or less than 100 microns. Also, for example, the depth may be at least half of the overall thickness of the diamond body, but the depth is no closer to the interface between the lower side of the diamond body and the upper side of the substrate than about 200 microns. Descriptions of leaching and of leached polycrystalline diamond cutters are contained in, for example, U.S. Pat. No. 4,224,380; U.S. Pat. No. 6,544,308 and U.S. Pat. No. 8,852,546, the entire contents of each are incorporated herein by reference.

The exemplary cutters described and disclosed herein can be incorporated in drilling tools used, for example, in drilling geological formations. Such drilling tools can incorporate flushing media supplied to the drill head to facilitate removing debris from the drilling zone as well as to remove heat from the drill head that is generated in the drilling operation. Examples of drilling tools include drag bits having polycrystalline diamond cutters arranged along a periphery region of a fin or blade.

FIG. 21 is a schematic, cut-away, partial view of an exemplary drilling tool with internal channels for cooling fluid and incorporating polycrystalline diamond cutters with a passage extending through the cutter on an axis. The exemplary drilling tool 2000 is illustrated in cross-sectional view along a diameter that includes a fin 2010 along the periphery so that structure related to the polycrystalline diamond cutters 2020, as well as the internal arrangement of features, is shown. Also, although only a half of the drilling tool 2000 is shown, the drilling tool 2000 is substantially rotationally symmetric about the axis 2030 so features shown here are analogous to the symmetrically located features on other portions of the drilling tool 2000.

The exemplary embodiment of a drilling tool comprises a body 2040 including a drill head 2050, a shoulder region 2060, and a shank portion 2070. The drill head 2050, shoulder region 2060 and shank portion 2070 are arranged axially along axis 2030. The shank portion can include an attachment structure, such as a threaded surface or fasteners, to attach the drilling tool 2000 to a drilling apparatus (not shown). The shoulder region 2060 provides a transition area between the drill head 2050 and shank portion 2070.

Mounted along the fin 2010 is a plurality of cutters 2020. At least a portion of the cutters 2020 are of the type disclosed and described herein with a substrate 2080, a diamond body 2090, and a first passage 2100 extending through the cutter 2020 along an axis from a first opening 2110 in the lower side of the substrate to a second opening 2120 in a first side of the diamond body 2090. These details are illustrated on one of the cutters 202) in FIG. 18, but apply equally to other cutters 2020 of the same type. Also, shown in FIG. 18 are cutters 2020 which do not have the first passage. The cutters 2020 are mounted by brazing the cutters 2020 in pockets in body 2040. For cutters 2020 with passages 2100, the passages 2100 are in fluid communication with the internal channels for cooling fluid of the drilling tool.

In exemplary embodiments, flushing media is supplied to the drill head 2040 via a network of internal channels. The internal channels include a central supply channel 2130 that is open at the shank portion 2070, e.g., for connecting to a supply line from the drilling apparatus, and a plurality of branching channels 2140 that connect the supply channel 2130 to individual outlets. The individual outlets can include the passages 2100 extending through the cutters 2020. Generally, the diameters of the branching channels 2140 are smaller than the diameter of the supply channel 2130, but the relative sizes of the diameters can be adjusted to achieve a desired flow rate of media through network of internal channels. The drilling tool 2000 can be manufactured by casting, for example by using a sand casting or lost-wax method, although machining can also be used to supplement the casting methods, particularly in connection with finish forming of the pockets for the cutters.

In operation, the fluid media, such as cooling fluid, supplied to the drill head 2050 flows through the branching channels 2140 and passages 2100 in the cutters 2020 and exits through the second opening 2120. Debris generated by the drilling action is flushed away from the drill head 2050 by the flow of the fluid media. Additionally, heat generated in the cutters 2020 by the drilling action is transported away from the heat generating regions through the diamond body's contact with a fluid medium in the passage 2100 as well as through the diamond body 2090 itself. In this last regard, the body 2040 of the drilling tool 2000 functions as a heat sink (which is in contact with the cutter 2020 via the braze joint 2150) and heat generated in the cutters is transported through the diamond body 2090 to the heat sink.

While reference has been made to specific embodiments, it is apparent that other embodiments and variations can be devised by others skilled in the art without departing from their spirit and scope. The appended claims are intended to be construed to include all such embodiments and equivalent variations. 

1. A polycrystalline diamond cutter, comprising: a substrate including an upper side, a lower side opposite the upper side, and at least one edge side connecting the upper side to the lower side; a diamond body including a planar oriented portion and a projecting portion; and a first passage extending through the cutter along an axis from a first opening in the lower side of the substrate to a second opening in a first side of the diamond body, wherein the planar oriented portion of the diamond body is attached to the upper side of the substrate, and wherein the projecting portion of the diamond body forms at least a portion of an inner wall surface of the first passage.
 2. The polycrystalline diamond cutter of claim 1, wherein the projecting portion of the diamond body forms the entire inner wall surface of the first passage
 3. The polycrystalline diamond cutter according to claim 1, wherein the planar oriented portion of the diamond body has a first side, a second side opposite the first side, and an outer edge side connecting the first side to the second side, and wherein the outer edge side is aligned with the at least one edge side of the substrate.
 4. The polycrystalline diamond cutter of claim 3, wherein the outer edge side transforms into a beveled surface.
 5. The polycrystalline diamond cutter according to claim 1, wherein the first side of the planar portion forms a right angle with the inner wall of the first passage.
 6. The polycrystalline diamond cutter according to claim 1, wherein the first side of the planar portion forms a non-right angle with the inner wall of the first passage.
 7. The polycrystalline diamond cutter according to claims claim 1, wherein the first side of the planar portion transforms into the inner wall of the first passage by a curved surface.
 8. The polycrystalline diamond cutter according to claim 1, wherein the first passage has a shape of a right cylinder.
 9. The polycrystalline diamond cutter according to claim 1, wherein the first passage has a shape of frustum of a cone.
 10. The polycrystalline diamond cutter according to claim 1, wherein the first passage has a shape of a one sheet hyperboloid.
 11. The polycrystalline diamond cutter according to claim 1, wherein a thickness of the projecting portion varies as a function of axial position. 12-13. (canceled)
 14. The polycrystalline diamond cutter according to claim 1, wherein an axial end of the projecting portion that is distal from the planar portion is aligned with the lower side of the substrate.
 15. The polycrystalline diamond cutter according to claim 1, wherein an axial length of the projecting portion is less than an axial length of the inner wall of the first passage.
 16. The polycrystalline diamond cutter according to claim 1, wherein the second side of the planar oriented portion is attached to the upper side of the substrate.
 17. The polycrystalline diamond cutter according to claim 16, wherein the second side of the planar oriented portion is planar.
 18. The polycrystalline diamond cutter according to claim 16, wherein the second side of the planar oriented portion is non-planar.
 19. The polycrystalline diamond cutter according to claim 16, wherein the second side of the planar oriented portion has a modulated surface texture.
 20. The polycrystalline diamond cutter according to claim 1, wherein the first passage extends axially along an axis coincident with a symmetry axis of the cutter and wherein the diamond body is continuous from the radial outer edge side to an axially most distant end of the projecting portion.
 21. The polycrystalline diamond cutter according to claim 1, wherein the first passage extends axially along an axis radially offset from a symmetry axis of the cutter
 22. The polycrystalline diamond cutter according to claim 21, wherein the diamond body is continuous from the radial outer edge side to an axially most distant end of the projecting portion. 23-42. (canceled) 